在VC中用API编程就可以了。可以用资源编辑器做出一个对话框的模板,在模板可加上TrackBar就可以实现标尺。如果想动态实现,可以这样做:
HWND WINAPI CreateTrackbar(
HWND hwndDlg, // handle of dialog box (parent window)
UINT iMin, // minimum value in trackbar range
UINT iMax, // maximum value in trackbar range
UINT iSelMin, // minimum value in trackbar selection
UINT iSelMax) // maximum value in trackbar selection
{
InitCommonControls(); // loads common control's DLL
hwndTrack = CreateWindowEx(
0, // no extended styles
TRACKBAR_CLASS, // class name
"Trackbar Control", // title (caption)
WS_CHILD and WS_VISIBLE and
TBS_AUTOTICKS and TBS_ENABLESELRANGE, // style
10, 10, // position
200, 30, // size
hwndDlg, // parent window
ID_TRACKBAR, // control identifier
g_hinst, // instance
NULL // no WM_CREATE parameter
);
SendMessage(hwndTrack, TBM_SETRANGE,
(WPARAM) TRUE, // redraw flag
(LPARAM) MAKELONG(iMin, iMax)); // min. & max. positions
SendMessage(hwndTrack, TBM_SETPAGESIZE,
0, (LPARAM) 4); // new page size
SendMessage(hwndTrack, TBM_SETSEL,
(WPARAM) FALSE, // redraw flag
return hwndTrack;
}
在对话框中可对WM_HSCROLL,WM_VSCROLL消息进行处理。在处理程序中对TRACKBAR进行控制。
VOID WINAPI TBNotifications(
WPARAM wParam, // wParam of WM_HSCROLL message
HWND hwndTrack, // handle of trackbar window
UINT iSelMin, // minimum value of trackbar selection
UINT iSelMax) // maximum value of trackbar selection
{
DWORD dwPos; // current position of slider
switch (LOWORD(wParam)) {
case TB_ENDTRACK:
dwPos = SendMessage(hwndTrack, TBM_GETPOS, 0, 0);
if (dwPos > iSelMax)
SendMessage(hwndTrack, TBM_SETPOS,
(WPARAM) TRUE, // redraw flag
(LPARAM) iSelMax);
else if (dwPos < iSelMin)
SendMessage(hwndTrack, TBM_SETPOS,
(WPARAM) TRUE, // redraw flag
(LPARAM) iSelMin);